Circuit breaker - associated backpack unit for lower-link communication with a PC computer monitoring system and energy monitoring system using a plurality of such backpack units

Abstract

A PC computer monitors the energy consumed at a plurality of local stations placed behind the electrical meter of the utility company for individual billing of the local users, a bidirectional communication line being used between the PC computer and the plurality of local stations. A command from the PC computer causes the totalized energy to be stored at each station, and thereafter the PC computer derives individually the results for separate energy estimations and central billing.

We claim: 
     
       1. A backpack unit to be associated with an installed local circuit interrupting device having a case and at least one terminal female lug for connection with a local cable conducting a current and a voltage for a load; the backpack unit comprising: electric circuitry to be oriented transversely of said circuit interrupting device local cable and having at least one central opening for admitting the local cable therethrough, said electric circuitry including transducer means for deriving analog signals representative of the local cable current and voltage; means for converting said analog signals into characteristic digital signals; digital means responsive to said digital characteristic signals for generating digital signals representative of local power consumed through the local cable; and connector means for outputting said power representative digital signals; and   a housing for said electric circuitry having a central opening corresponding to said at least one central opening of said electric circuitry, the central openings of said electric circuitry and said housing admitting the local cable therethrough in order that the local cable current flows between the local cable and said circuit interrupting device terminal female lug, such that the local cable current remains external to the backpack unit, said housing including a male plug disposed therein and connected to said transducer means, said male plug extending therefrom and projecting outside the housing and external to the backpack unit for connection to said circuit interrupting device terminal female lug in order to mount the backpack unit against said case of said installed local circuit interrupting device, and in order to provide to said transducer means the local cable voltage.   
     
     
       2. The backpack unit of claim 1 with said housing having a cross-section in a plane of said electric circuitry equal at most to a cross-section of said circuit interrupting device case projecting in a plane normal to said local cable. 
     
     
       3. The backpack unit of claim 2 with a bidirectional communication line means being provided connected to a computer and to said electric circuitry; said computer communicating digitally and asynchronously with said digital means for directly initiating operation of said generating means and for outputting said power representative signals. 
     
     
       4. The backpack unit of claim 3 with said communication line means including a lower-link module for converting said representative digital signals into a digitally coded value of said local power consumed, said digitally coded value being given a message format for asynchronous and sequential transmission through said communication line mans: 
     
     
       5. The backpack unit of claim 4 with said lower-link module being addressed by said computer through said communication line means for directly initiating the derivation of an instantaneous value of said local power consumed. 
     
     
       6. A system associated with a plurality of installed circuit interrupting devices disposed on a common panelboard with respective corresponding cases, female terminal lugs and local cables each local cable conducting a current and a voltage for a load; backpack units of the same plurality being provided, each backpack unit being mounted against a corresponding one of said circuit interrupting device cases for outputting digital signals representative of local power consumed at the corresponding location for a local cable, each backpack unit having an opening admitting the corresponding local cable therethrough in order that the current of the corresponding local cable flows between the corresponding local cable and the corresponding female terminal lug, such that the current of the corresponding local cable remains external to the corresponding backpack unit but induces a sensed current signal representative of the current of the corresponding local cable in a transducer means within the corresponding backpack unit, each backpack unit also having external means providing an internal sensed voltage signal representative of the voltage of the corresponding local cable and internal means calculating power from said sensed current and voltage signals; a bidirectional communication line means being established serially between a computer and coupled with respective lower-link modules of the several backpack units for the respective locations; the computer communicating selectively and instantaneously with said backpack units for deriving an indication of the local power consumed at the respective locations. 
     
     
       7. The system of claim 6 having a collective electrical meter for computing energy consumed in distribution of electricity for use through said local cable and the computer recording and calculating through said communication line means and with the lower-link of each of said backpack units the energy consumed individually at said respective locations. 
     
     
       8. The backpack unit of claim 6 wherein said circuit interrupting device is a circuit breaker. 
     
     
       9. A backpack unit to be associated with an installed local circuit interrupting device having a molded case and at least one terminal female lug for connection with a local cable providing a current and a voltage for a load; the backpack unit comprising: two parallel and side-by-side printed-circuit (PC) boards to be oriented transversely of said circuit interrupting device local cable and having at least one central common opening for admitting the cable therethrough;   one of said PC boards including transducer means for deriving analog signals representative of the local cable current and voltage;   said other PC board having:   means for converting said analog signals into characteristic digital signals; digital means responsive to said digital characteristic signals for generating digital signals representative of local power consumed through the local cable; and connector means for outputting said power representative digital signals;   said two PC boards being connected laterally for passing said analog signals from said one PC board to said other PC board; and   a housing for said two PC boards having a central opening corresponding to said at least one central common opening of said two PC boards, the central common opening of said two PC boards and the central opening of said housing admitting the local cable therethrough in order that the current of the local cable flows between the local cable and said circuit interrupting device terminal female lug, such that the current of the local cable remains external to the backpack unit, said housing including a male plug disposed therein and connected to said transducer means, said male plug extending therefrom and projecting outside the housing and external to the backpack unit for connection to said circuit interrupting device terminal female lug in order to mount the backpack unit against said case and on said installed circuit interrupting device, and in order to provide to said transducer means the voltage of the local cable.   
     
     
       10. The backpack unit of claim 9 wherein said circuit interrupting device is a circuit breaker.